JP5751166B2 - Bearing remaining life prediction method, remaining life diagnosis device, and bearing diagnosis system - Google Patents

Description

  The present invention relates to a bearing remaining life prediction method, a remaining life diagnosis apparatus, and a bearing diagnosis system. More specifically, the present invention relates to a bearing incorporated in a user's mechanical apparatus before the bearing is damaged due to progress of fatigue. The present invention relates to a bearing remaining life prediction method, a remaining life diagnosis apparatus, and a bearing diagnosis system that can predict a life.

  Steel mills, paper mills, and the like use a large number of rolls that are rotatably supported by bearings. In such factories, each factory monitors and diagnoses the life of bearings with vibration sensors, etc., and performs parts replacement plans, requests for quotations from bearing manufacturers, and orders. However, in the diagnosis of a factory that does not specialize in bearings, it may be difficult to accurately diagnose the bearing life due to equipment and technical problems. Many replacement bearings are stocked in preparation for sudden accidents. It is common to leave. In addition, bearing manufacturers are required to prepare a large number of stocks and sales personnel in preparation for orders that fluctuate frequently and suddenly.

  In order to deal with such problems, the sensor is installed on the bearing used by the user, the vibration waveform, temperature, image, etc. of the bearing are measured, and the signal transmitted from the sensor is captured at a remote location. There is provided a monitoring / diagnosis system and method for the bearing manufacturer to perform bearing life diagnosis from a remote location (see, for example, Patent Document 1). In Patent Document 1, by detecting the abnormal initial state of the bearing, the mechanical equipment is stopped before the damage of the bearing expands to prevent the influence on the manufactured product and the serious damage of the incidental equipment. The necessary bearings are ordered at an early stage so that replacement can be carried out smoothly, and the number of required replacement bearings is optimized to improve inventory management efficiency.

  Further, when fatigue occurs in the bearing material, changes occur in the structure of the bearing material, such as martensitic transformation of retained austenite, a decrease in dislocation density, and an increase in compressive residual stress. As a technique for predicting the degree of fatigue progress of a bearing, a technique has been devised in which the degree of fatigue progress is estimated by measuring a structural change using X-rays (see, for example, Patent Document 2). Also, although it is not a bearing, it measures the change in magnetic permeability caused by the transformation of the austenite phase to the martensite phase due to work transformation by eddy current, and predicts the fatigue level of an austenitic stainless steel specimen. It is known (for example, refer to Patent Document 3). Furthermore, a bearing load state diagnosis method is known in which a decrease in retained austenite is measured using eddy current (see, for example, Patent Document 4).

JP 2001-356808 A Japanese Patent Publication No. 63-34423 JP-A-8-248004 JP 2004-198246 A

  By the way, the technique of Patent Document 1 that detects the presence or absence of abnormality based on the vibration waveform, temperature, image, etc. of the bearing can determine whether or not the bearing is in a normal state unless any abnormality occurs in the bearing. Can not. Therefore, although it is possible to prevent damage to the bearing and the impact on the manufactured product and to prevent serious damage to the incidental equipment, the influence on the manufactured product due to the bearing damage and the occurrence of accidents on the incidental equipment cannot be reduced to zero. There wasn't. In addition, since the bearing is ordered after the bearing is damaged, in the worst case, the facility must be stopped for a period from the ordering by the user until the delivery, and the facility operation rate is lowered. There's a problem. In particular, when bearing damage suddenly occurs, the user may not be in stock, and the equipment stoppage may be prolonged.

  In addition, the technique of Patent Document 2 that predicts the degree of fatigue progression of a bearing measures the structural change of the bearing material using X-rays, so that it is difficult to perform on-site measurement and is a destructive inspection. was there. Patent Document 3 is a technique for measuring a change from an austenite phase to a martensite phase for an inspected object made of austenitic stainless steel. In the case of a rolling bearing, a change due to fatigue is a change in the amount of retained austenite. Therefore, it is not possible to accurately predict the fatigue level of a rolling bearing only by measuring the change in permeability with eddy current. Further, with the technique according to Patent Document 4, although the load state of the bearing can be diagnosed, the remaining life cannot be estimated.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to non-destructively inspect a bearing used by a user and predict a remaining life of the bearing, and a remaining life prediction method and remaining life diagnosis. It is to provide a device and a bearing diagnosis system.

The above object of the present invention can be achieved by the following constitution.
(1) A method for predicting the remaining life of a bearing incorporated in a mechanical device,
Measuring the impedance of the bearing with an eddy current measuring device while the bearing is stationary;
Determining the remaining life of the bearing based on the measured impedance of the bearing;
Equipped with a,
The remaining life of the bearing is the relationship between the impedance distance and the remaining life of the bearing after obtaining the impedance distance, which is the difference between the measured impedance values before and after use of the bearing measured by the eddy current measuring device. A remaining life prediction method for a bearing characterized in that it is obtained with reference to the graph shown .
(2) The remaining life of the bearing is
The impedance of the raceway surface or rolling surface of the bearing before use, measured by the eddy current measuring device,
The impedance of the raceway surface or the rolling surface in the bearing after use, measured by the eddy current measuring device,
The bearing remaining life prediction method according to the above (1) , characterized in that it is obtained based on the difference between the two.
(3) The remaining life of the bearing is
Measured by the eddy current measurement device, the impedance of the orbital plane that put in a non-loaded zone of the bearing,
The measured by eddy current measuring device, the impedance of the orbital plane of the load zone in the bearing after use,
The bearing remaining life prediction method according to the above (1) , characterized in that it is obtained based on the difference between the two.
(4) The remaining life of the bearing is
The impedance of the end face of the bearing measured by the eddy current measuring device;
The measured by eddy current measuring device, the impedance of the orbital plane of the load area that put on the bearing after use,
The bearing remaining life prediction method according to the above (1) , characterized in that it is obtained based on the difference between the two.
(5) A remaining life diagnosis device for predicting the remaining life of a bearing incorporated in a mechanical device,
An eddy current measuring device for measuring the impedance of a predetermined part of the bearing before and after use of the bearing;
After obtaining the impedance distance, which is the difference between the measured impedance values before and after use of the bearing measured by the eddy current measuring device, with reference to a graph showing the relationship between the impedance distance and the remaining life of the bearing , A diagnostic unit for determining the remaining life of the bearing;
A remaining life diagnosis apparatus for bearings, comprising:
(6) A bearing diagnosis system incorporated in a user's mechanical device,
An eddy current measuring device that measures the impedance of a predetermined portion of the bearing while the bearing is stationary;
A bearing information transmitting unit that transmits bearing information including the impedance of the bearing measured by the eddy current measuring device and individual identification information of the bearing to a bearing manufacturer;
A bearing information receiver that receives the bearing information transmitted from the bearing information transmitter;
Based on the received impedance provided on the bearing manufacturer side, after obtaining an impedance distance that is a difference between measured values of the impedance before and after use of the bearing measured by the eddy current measuring device, the impedance distance and Referring to a graph showing the relationship with the remaining life of the bearing, a diagnostic unit for obtaining the remaining life information of the bearing;
A lifetime information transmitting unit that transmits the remaining lifetime information obtained by the diagnostic unit to the user;
A lifetime information receiving unit that receives the remaining lifetime information transmitted from the lifetime information transmitting unit;
A bearing diagnosis system comprising:
(7) The diagnosis unit includes a database in which related information between bearing information and the remaining life of the bearing is accumulated, and the bearing is based on the database and the bearing information received by the bearing information receiving unit. The bearing diagnosis system according to (6) , wherein the remaining life of the bearing is obtained.

According to the bearing remaining life prediction method and remaining life diagnostic apparatus of the present invention, the impedance of the bearing is measured nondestructively with an eddy current measuring device to detect changes in the material structure and hardness of the bearing surface and surface layer. The damage time of the bearing, that is, the remaining life of the bearing can be predicted before the bearing is damaged due to fatigue.
In particular, the remaining life can be predicted with high accuracy by obtaining the remaining life based on the difference in impedance measurement values (impedance distance) before and after the use of the bearing.

  Further, according to the bearing diagnostic system of the present invention, the bearing manufacturer can receive the impedance measured by the eddy current measuring device at a remote place and analyze it at the diagnostic unit, thereby predicting the remaining life of the bearing. . In addition, the remaining life can be transmitted to the user before the bearing actually fails. As a result, the user can arrange and replace the bearings in advance, and the influence on the manufactured product, the incidental equipment, and the manufacturing schedule can be minimized. Furthermore, it is possible to preset a line schedule for bearing replacement, thereby reducing maintenance costs and minimizing equipment downtime and improving production efficiency. In addition, since the sensor measures with the bearing stationary, a more accurate diagnosis than the diagnosis during operation of the bearing is possible.

It is a schematic block diagram of the remaining life diagnosis apparatus of the bearing which concerns on this invention. It is a figure which shows the state which measures the impedance of a bearing with an eddy current measuring apparatus. It is a graph which shows the impedance before and behind use of a bearing. FIG. 4A is a graph showing the relationship between the impedance distance and the remaining life, and FIG. 4B is a graph showing the relationship between the impedance distance and the fatigue progress. (A) And (b) is a figure which shows the state which measures the impedance of the load zone and non-load zone of an outer ring raceway surface with an eddy current measuring apparatus. It is a figure which shows the state which measures the impedance of the end surface of a bearing, and the outer ring raceway surface of a load zone with an eddy current measuring apparatus. 1 is a block diagram of a bearing diagnosis system according to the present invention. It is a conceptual diagram which shows the flow of information of the bearing diagnostic system shown in FIG. It is explanatory drawing of the structural example of the bearing diagnostic system shown in FIG. It is a graph which shows the relationship between fatigue progress and each change rate of a retained austenite, the half value width of a martensite, and a raceway surface roughness.

  Embodiments of a remaining life prediction method and a remaining life diagnosis apparatus according to the present invention will be described below in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a schematic configuration diagram of a bearing remaining life diagnosis device according to the present invention. A remaining life diagnosis device 10 includes an eddy current measuring device 11, a diagnosis unit 12 for determining the remaining life of a bearing, an input unit 13, and a display unit 14. It has. The eddy current measurement device 11 and the diagnosis unit 12 are mainly configured by a so-called computer. The eddy current measurement device 11 is connected to a probe 15 for measuring the impedance of a predetermined part of the bearing. The database 33 in which the correlation between the impedance and the remaining life (fatigue progress) is accumulated is connected.

  The eddy current measuring device 11 induces an eddy current in a metal to be measured (here, an outer ring, an inner ring, or a rolling element of a bearing) by passing an exciting current through a coil (not shown) in the probe 15, and the eddy current. By detecting the impedance generated in the coil, the measurement of the metal structure (for example, the amount of retained austenite) is measured nondestructively.

  Based on the impedance measured by the probe 15, the diagnosis unit 12 obtains the remaining life of the bearing by referring to the correlation between the impedance accumulated in the database 33 and the remaining life (fatigue progress) and displays it on the display unit 14. To do.

  FIG. 2 is a diagram showing a state in which the impedance of the outer ring raceway surface of the bearing is measured by an eddy current measuring device. First, the probe 15 is brought close to the raceway surface 16a of the outer ring 16 in the unused state, and the raceway surface when not in use. The impedance X1 of 16a is measured and stored in the database 33 together with the identification number of the bearing to be measured. Next, when the usage time of the bearing reaches a predetermined operation time such as during regular maintenance of the bearing, the bearing is disassembled, and the impedance X2 of the raceway surface 16a after use is measured.

  FIG. 3 is a graph showing the impedance before and after the use of the bearing, FIG. 4A is a graph showing the relationship between the impedance distance and the remaining life, and FIG. 4B is a graph showing the relationship between the impedance distance and the fatigue progress. is there. The relationship between the impedance distance and the remaining life (fatigue progress) shows different characteristics for each bearing material such as stainless steel and high carbon bearing steel, and data for each bearing material is accumulated in the database 33. As shown in FIG. 2, impedances X1 and X2 of the raceway surface 16a of the outer ring 16 measured before and after use of the bearing are plotted on a graph as shown in FIG. 3, and are the differences between the two impedances X1 and X2. The impedance distance A is obtained. The impedance plan view shown in FIG. 3 shows the locus of the coordinates of the impedance with the horizontal axis representing the resistance component of the impedance and the vertical axis representing the reactance component. Next, the diagnosis unit 12 refers to the relationship between the impedance distance A and the remaining life L (fatigue progress F) stored in the database 33 shown in FIG. L or fatigue progression degree F is obtained.

  If a plurality of threshold values, for example, two threshold values are set for the impedance distance A, and the remaining life L is displayed in three stages (for example, normal, caution, warning, etc.) based on the threshold values, This is an easy-to-understand index for the remaining life L. It is desirable that the remaining life diagnosis based on the impedance measurement is performed during a period of use of the bearing, for example, every fixed operation time, that is, periodically several times and accumulated in a database.

  Here, as a result of investigating the relationship between the structure and surface properties of many bearings used in the market and the eddy current measurement value, in the case of rolling fatigue, the applicant has measured the permeability, conductivity, We found complex behavior due to changes in circuit coupling, etc., but we found that they move regularly on the impedance plot as rolling fatigue progresses. In addition, by building a database of the relationship between fatigue progress and impedance plot, we succeeded in building a system that can predict the remaining life from eddy current measurements.

  Since the bearing rings and rolling elements of rolling bearings are manufactured through many processes such as forging, turning, heat treatment, polishing, etc., the material structure and surface properties of the bearings are in some initial (unused) state. Have variations. On the other hand, the measured value of eddy currents is sensitive to the slight difference in material structure and surface properties, so even if the fatigue progress is the same, the numerical value of the impedance may be different for each bearing. Therefore, rather than obtaining the degree of fatigue progression from the absolute value of the impedance value obtained by eddy current measurement, the method for obtaining the degree of fatigue progression from the difference (impedance distance) between the initial (unused) impedance and the impedance after using the bearing However, it is possible to estimate the remaining life with high accuracy.

  As described above, according to the remaining life prediction method and remaining life diagnosis device 10 of the present embodiment, the eddy current measurement device 11 measures the impedance X of a predetermined portion of the bearing in a nondestructive manner, and the diagnosis unit 12 measures the impedance X. Since the remaining life L of the bearing is determined based on the impedance X, the bearing surface, the material structure change of the surface layer, the hardness change, and the like, which are indicators of the fatigue progress F, are detected, and the bearing is damaged due to the progress of fatigue. Before starting, the bearing damage timing, that is, the remaining life L of the bearing can be predicted. In particular, the remaining life L can be predicted with high accuracy by obtaining the remaining life L based on the difference between the measured values of the impedance X before and after the use of the bearing (impedance distance A). Further, if the remaining life diagnosis device 10 is an independent portable device, the remaining life L can be predicted at the use site of the bearing.

  If it is difficult to measure the impedance X1 of the raceway surface before using the bearing, as shown in FIGS. 5A and 5B, the non-load zone (on the bearing) of the stationary member (outer ring 16) of the bearing The impedance X1 ′ measured on the raceway surface 16a on the side opposite to the acting load P) can be substituted as the impedance X1 of the bearing before use. Moreover, as shown in FIG. 6, you may use impedance X1 'measured on the end surface 16b of a bearing (outer ring | wheel 16) as the impedance X1 of a bearing before use.

  The impedance X is preferably measured not only on the outer ring 16 but also on the raceway surface of the inner ring and the rolling surface of the rolling element. The shortest value of the three remaining lifetimes based on these three impedance distances A is determined. It is desirable that the remaining life L be used.

(Second Embodiment)
Next, an embodiment of a bearing diagnosis system according to the present invention will be described in detail with reference to the drawings.
As shown in FIGS. 7 to 9, the bearing diagnosis system 20 diagnoses the bearing 24 of the mechanical device 23 installed in the user 22 in the bearing manufacturer 21 and returns the remaining life information of the bearing 24 to the user 22. System.

  The bearing 24 to be diagnosed by the bearing diagnostic system 20 is a bearing used by being incorporated in a mechanical device 23 such as a windmill, a railway vehicle, a steel facility in a steel mill, a papermaking machine in a paper mill, or a construction machine in a mine. It is. The remaining life information of the bearing 24 is obtained by the diagnostic unit 12 provided on the bearing manufacturer 21 side based on the measured value (impedance X) regarding the physical quantity inside the bearing material measured by the eddy current measuring device 11. Specifically, the diagnosis unit 12 obtains remaining life information from the impedance X measured when the probe 15 is brought close to the bearing 24 that is a sample.

  The user 22 is provided with a bearing information transmission unit 30 that transmits bearing information s1 including a measured value of impedance measured by the eddy current measuring device 11 to the Internet (public line) 29. The bearing information transmission unit 30 includes an information collection unit 30a and an information transmission unit 30b. The bearing information s1 includes individual identification information such as the user name of the target bearing 24, the machine device 23 used, the location used, the usage condition, the usage environment, and the cumulative usage time.

  The bearing information transmission unit 30 is not particularly limited as long as it can transmit the bearing information s1 to the Internet 29, and a computer, various information processing devices, and the like can be used. What has a memory | storage part which memorize | stores the bearing information s1 containing identification information is preferable.

  The bearing manufacturer 21 includes a bearing information receiving unit 31 that receives bearing information s1 transmitted from the user 22 via the Internet 29, and a diagnostic unit 12 that diagnoses the remaining life of the bearing 24 from the bearing information s1. The bearing manufacturer 21 is provided with a product information adding unit 35, a life information transmitting unit 36, and an order receiving processing unit 37. If the bearing information receiving unit 31 and the diagnostic unit 12 are arranged in the technical research department 21A, and the product information adding unit 35, the life information transmitting unit 36, and the order receiving processing unit 37 are provided in the sales and production department 21B, various information can be efficiently transmitted. Can be handled easily.

  The bearing information receiving unit 31 can receive the bearing information s1 transmitted from the bearing information transmitting unit 30 of the user 22 via the Internet 29, and can identify the user 22 that has transmitted the bearing information s1. . The bearing information receiving unit 31 may be a general-purpose information processing device having a communication function such as a computer or a dedicated electronic device, and has an information storage unit (not shown) for storing the received bearing information s1. Is preferred.

  The diagnosis unit 12 includes a database 33 in which related information between the bearing information s1 and the remaining life (fatigue progress) of the bearing 24 is accumulated. From the impedance X measured by the eddy current measurement device 11, the diagnosis unit 12 stores The remaining life of the bearing 24 is obtained based on the accumulated data.

  The product information adding unit 35 is connected to a database 34 that stores product information such as model-specific inventory information, price information, and delivery date information. The product information adding unit 35 stores the remaining life information s2 obtained by the diagnosis unit 12 in the database 34. Necessary product information is extracted and added from the accumulated data to obtain bearing life information s3. The bearing life information s3 is transmitted from the life information transmitting unit 36 to the life information receiving unit 40 installed in the user 22.

  FIG. 9 is a hardware configuration example of the bearing diagnosis system 20. A plurality of computers 41 and 42 and a database 33 constituting a local area network include a terminal adapter 43, a router 44, and a hub 45 with respect to the Internet 29. And is managed by the web server 46. The database 33 includes a computer 47 and a large capacity storage unit 48, and the bearing information reception unit 31 includes a router 44, a hub 45, a web server 46, and the like. The diagnosis unit 12 includes a computer 41 and the like.

  In the sales and production department 21B of the bearing manufacturer 21, a plurality of computers 49 and 50 and a product information database 34 constitute a local area network and are connected to the Internet 29 via a terminal adapter 51, a router 52 and a hub 53. And managed by the web server 54. The product information adding unit 35, the life information transmitting unit 36, and the order receiving processing unit 37 are configured by computers 49 and 50.

  The user 22 configures a local area network with a plurality of computers 56 and a controller serving as the bearing information transmission unit 30, and is connected to the Internet 29 via a terminal adapter 57, a router 58, and a hub 59. Managed by. The life information receiving unit 40 includes a computer 56.

When there are a plurality of users 22, as shown in FIG. 9, the bearing information receiving unit 31 (router 44, hub 45, web server 46) and life information transmitting unit 36 (computers 49, 50) of the bearing manufacturer 21 are connected to the Internet. 29 are connected to computers 56 and 61 constituting the bearing information transmitting unit 30 and the life information receiving unit 40 of each user 22.
In the conceptual diagram of FIG. 8 showing the information flow of the bearing diagnosis system of FIG. 7, reference numeral 30 ′ is a data collection unit controller constituting the bearing information transmission unit 30, and 31 ′ is a bearing information reception unit. An information management interface is configured, 26 is a technology / research department data analysis configuring the diagnosis unit 12, 33 ′ represents database creation for creating the fatigue database 33, and 35 ′ represents a product information addition unit 35. , Sales department maintenance support having a life information transmission unit 36 and an order processing unit 37 is shown.

  The diagnostic method of this embodiment will be described. As shown in FIG. 7, the user 22 stops the mechanical device 23, disassembles the bearing 24, and measures the impedance X of the raceway surface by the eddy current measuring device 11 (see FIG. 2). The impedance X of the bearing 24 can be accurately measured as long as the bearing 24 is stationary. The bearing 24 is disassembled, and each of the raceway surface 16a of the outer ring 16, the raceway surface of the inner ring, and the rolling surface of the rolling element is obtained. By measuring the impedance X for, it can be measured more accurately.

  The bearing information s1 including the measured value of the impedance X measured by the eddy current measuring device 11 and the individual identification number of the bearing 24 is transmitted from the bearing information transmitting unit 30 via the Internet 29 and received by the bearing manufacturer 21. Received by the unit 31. Based on the data stored in the database 33, the diagnosis unit 12 obtains the remaining life of the bearing 24 based on the bearing information s1 received by the bearing information receiving unit 31.

  Specifically, the database 33 includes the impedance X1 (when periodically measured) of the bearing 24 before use, together with related information (which differs for each bearing material) between the impedance distance A and the remaining life (fatigue progress). (Including the measurement history of the impedance X of each time) in association with the individual identification information, and the stored impedance X1 of the bearing 24 before use and the use included in the bearing information s1 transmitted this time. The impedance distance A is obtained from the impedance X2 of the subsequent bearing 24, and the remaining life is obtained from the impedance distance A based on the data in the database 33 (see FIGS. 3 and 4).

  Note that the remaining life calculation procedure is the same as in the first embodiment, and a description thereof will be omitted. If there is a measurement history of impedance X, it is preferable to obtain the remaining life with reference to the measurement history.

  If the impedance X1 of the bearing 24 before use is not stored in the database 33, the impedance X of the end face of the bearing 24, or the raceway surface or rolling surface of the non-load zone can be substituted (FIGS. 5 and 6). reference). Furthermore, although the accuracy is somewhat rough, it is possible to obtain the remaining life only from the impedance X2 of the bearing 24 after use.

  The remaining life obtained by the diagnosis unit 12 is added with information such as an individual identification number, a bearing part such as an outer ring, an inner ring, and a rolling element of the bearing 24 to be diagnosed, an application, etc., and becomes remaining life information s2. The remaining life information s2 includes product information that is considered necessary, such as model-specific inventory information, price information, and delivery date information, and order inquiry information from the data stored in the product information database 34 as necessary. The bearing life information s3 is added and transmitted from the life information transmission unit 36 to the life information reception unit 40 of the user 22.

  The order processing unit 42 provided in the life information receiving unit 40 transmits the order information s4 to the order receiving processing unit 37 via the Internet 29 based on the estimation information included in the bearing life information s3. The order processing unit 37 transmits delivery arrangement information to the product storage unit 71 in accordance with the order contents of the order information s4. The product storage unit 71 produces the bearing 24 in the product production unit 72 according to the received arrangement information, and delivers it to the user 22.

  As described above, according to the bearing diagnosis system 20 of the present embodiment, the bearing information s1 including the impedance X of the bearing 24 measured by the eddy current measuring device 11 and the individual identification information of the bearing 24 is in a remote place. Based on the data received by the bearing manufacturer 21 and accumulated in the database 33, the remaining life of the bearing 24 can be obtained by the diagnosis unit 12, and the remaining life information s2 can be transmitted to the user 22 before the bearing 24 fails. . That is, status information related to the remaining life of the bearing can be measured and the remaining life information s2 can be predicted in a state where the bearing 24 is normally used before external damage to the bearing 24 occurs. Therefore, it is possible to obtain a longer period for maintenance and inventory adjustment. Thereby, the user 22 can arrange and exchange the bearing 24 in advance, and can suppress the influence which it has on a manufactured product, incidental equipment, and a manufacturing schedule to the minimum. In addition, a line schedule for bearing replacement can be set in advance, so that maintenance costs can be reduced, and the facility downtime can be minimized to improve production efficiency.

  Here, in order to confirm how each factor changes as fatigue progresses, the durability test is stopped halfway, the amount of change in retained austenite, the amount of change in the half-value width of martensite, the surface roughness of the raceway surface. We investigated the relationship between the amount of change.

A self-aligning roller bearing (model number 22211) was used as the test bearing. The test conditions were as follows: test load was radial load Fr = 4614 kg, axial load Fa = 0 kg, rotation speed was n = 1500 min ⁻¹ , and lubricating oil (ISO-VG68) was forcibly circulated. The test was stopped at 1 h, 5 h, 10 h, 50 h, 100 h, 500 h, and 1000 h, and the amount of retained austenite, the half-value width of martensite, and the surface roughness were measured. The amount of retained austenite and the half width of martensite were measured using X-ray diffraction. Further, the surface roughness was measured using a foam Talysurf manufactured by Taylor Hobson. FIG. 10 shows the relationship between the degree of progress of fatigue, the surface roughness, the amount of retained austenite, and the half-value width of martensite. The definition of the degree of progress of fatigue is (operation time during measurement / peeling time), and the amount of change on the vertical axis in FIG.

  As shown in FIG. 10, it can be seen that at the very initial stage of the fatigue process, the surface roughness changes, the half-value width of martensite subsequently changes, and finally the change in the amount of retained austenite appears. Therefore, it is possible to predict the remaining life by measuring the change in surface roughness in the early stage of fatigue, the half-value width of martensite in the middle period, and the change in retained austenite at the end stage.

(Example)
Hereinafter, an embodiment to which the bearing diagnosis system 20 and the bearing diagnosis method according to the present invention are applied will be described.
1. Steelworks Many mill rolls are used in each facility. For example, in a continuous casting facility, about several hundred rolls are used, and usually two bearings are arranged on each roll, so that the total number of bearings used is several thousand. If even one of the hundreds of rolls causes a rotation failure, the shape of the product (slab) may be greatly affected. Therefore, according to the conventional diagnostic system in which a bearing abnormality is detected after the bearing is damaged, there is a risk that the product as well as the equipment may be damaged greatly. The bearing diagnosis system of the present invention can check the bearing status (residual life) before the bearing is damaged, so that it is possible to prevent sudden equipment damage and to set a line schedule for bearing replacement in advance. Cost can be reduced.

2. Paper Mills A number of rolls are used in paper mills as well as in steel mills. For this reason, when the bearing used for the roll is damaged, it is expected that the bearing will be greatly affected as in the case of the steel equipment, but it can be avoided by the bearing diagnostic system of the present invention.

3. Wind power generation Wind power generation has a larger power generation capacity year by year, and in recent years, large-scale wind turbines of multi-megawatt class (5 MW or more) have been installed. Many are installed onshore, but they are beginning to be installed offshore due to restrictions on transportation, installation, and the surrounding environment. In wind power generation, a rotor is rotated by wind power, and the speed is increased to a predetermined number of rotations by a speed increaser to rotate the generator, thereby converting mechanical energy into electric energy. These gearboxes and generators are housed in a hangar called nacelle, but are installed at a high place (100m or more) according to the position of the rotor. If an abnormality occurs in the bearing, it will not be able to generate power, but it will also have a significant impact on peripheral members (gears, generators). As a result, the bearing diagnosis system according to the present invention can grasp the bearing state in advance, and as a result, the bearing is replaced. Since power transmission control and replacement scheduling can be performed in advance, power generation cost loss can be minimized, and replacement before the bearing is damaged prevents damage to other peripheral members. be able to

4). Mine Construction Machinery Mine mines are often located in remote areas such as high altitude mountains, and bearings used in such places as bulldozers, dump trucks, or mining machines are damaged. A lot of labor and cost are required for replacement. According to the bearing diagnostic system of the present invention, since the remaining life of the bearing can be known in advance, loss due to bearing damage, maintenance labor and cost can be minimized.

Note that the present invention is not limited to the above-described embodiments and examples, and modifications, improvements, and the like can be made as appropriate.
For example, the impedance measured at the user's factory, along with the individual identification number such as the bearing part number, and the relationship information between the impedance and the remaining life are input to the IC tag and passed to the user, and the remaining life of the bearing at the user's site. May be determined.

  Further, in this embodiment, the impedance X of the raceway surface is measured by the eddy current measuring device 11 with the mechanical device 23 stopped and the bearing 24 disassembled. You may make it measure, without disassembling 24. FIG. When the bearing 24 is not disassembled, the measurement may be performed at the timing when the mechanical device 23 is stopped, or the mechanical device 23 may be stopped and periodically measured.

Furthermore, in the present embodiment, the impedance X of the raceway surface before and after use is measured by the eddy current measuring device 11, but surface damage generated on the raceway surface of the bearing is detected by an optical sensor, and this measurement result is Based on this, the remaining life may be obtained.
The present invention is based on a Japanese patent application filed on December 17, 2009 (Japanese Patent Application No. 2009-286398) and a Japanese patent application filed on January 29, 2010 (Japanese Patent Application No. 2010-017802). The contents are incorporated herein by reference.

DESCRIPTION OF SYMBOLS 10 Remaining life diagnostic apparatus 11 Eddy current measuring apparatus 12 Diagnosis part 16 Outer ring 16a Raceway surface 16b End face 20 Bearing diagnosis system 21 Bearing manufacturer 22 User 23 Mechanical device 24 Bearing 30 Bearing information transmission part 31 Bearing information reception part 33 Database 36 Life information transmission 40 Life information receiver A Impedance distance L Remaining life s1 Bearing information s2 Remaining life information X, X1, X2 Impedance

Claims (7)

A remaining life prediction method for predicting a remaining life of a bearing incorporated in a mechanical device,
Measuring the impedance of the bearing with an eddy current measuring device while the bearing is stationary;
Determining the remaining life of the bearing based on the measured impedance of the bearing;
Equipped with a,
The remaining life of the bearing is the relationship between the impedance distance and the remaining life of the bearing after obtaining the impedance distance, which is the difference between the measured impedance values before and after use of the bearing measured by the eddy current measuring device. A remaining life prediction method for a bearing characterized in that it is obtained with reference to the graph shown . The remaining life of the bearing is
The impedance of the raceway surface or rolling surface of the bearing before use, measured by the eddy current measuring device,
The impedance of the raceway surface or the rolling surface in the bearing after use, measured by the eddy current measuring device,
The bearing remaining life prediction method according to claim 1 , wherein the remaining life of the bearing is predicted based on the difference between the two. The remaining life of the bearing is
Measured by the eddy current measurement device, the impedance of the orbital plane that put in a non-loaded zone of the bearing,
The measured by eddy current measuring device, the impedance of the orbital plane of the load zone in the bearing after use,
The bearing remaining life prediction method according to claim 1 , wherein the remaining life of the bearing is predicted based on the difference between the two. The remaining life of the bearing is
The impedance of the end face of the bearing measured by the eddy current measuring device;
The measured by eddy current measuring device, the impedance of the orbital plane of the load area that put on the bearing after use,
The bearing remaining life prediction method according to claim 1 , wherein the remaining life of the bearing is predicted based on the difference between the two. A remaining life diagnosis device for predicting the remaining life of a bearing incorporated in a mechanical device,
An eddy current measuring device for measuring the impedance of a predetermined part of the bearing before and after use of the bearing;
After obtaining the impedance distance, which is the difference between the measured impedance values before and after use of the bearing measured by the eddy current measuring device, with reference to a graph showing the relationship between the impedance distance and the remaining life of the bearing , A diagnostic unit for determining the remaining life of the bearing;
A remaining life diagnosis apparatus for bearings, comprising: A bearing diagnostic system incorporated in a user's machine,
An eddy current measuring device that measures the impedance of a predetermined portion of the bearing while the bearing is stationary;
A bearing information transmitting unit that transmits bearing information including the impedance of the bearing measured by the eddy current measuring device and individual identification information of the bearing to a bearing manufacturer;
A bearing information receiver that receives the bearing information transmitted from the bearing information transmitter;
Based on the received impedance provided on the bearing manufacturer side, after obtaining an impedance distance that is a difference between measured values of the impedance before and after use of the bearing measured by the eddy current measuring device, the impedance distance and Referring to a graph showing the relationship with the remaining life of the bearing, a diagnostic unit for obtaining the remaining life information of the bearing;
A lifetime information transmitting unit that transmits the remaining lifetime information obtained by the diagnostic unit to the user;
A lifetime information receiving unit that receives the remaining lifetime information transmitted from the lifetime information transmitting unit;
A bearing diagnosis system comprising: The diagnosis unit includes a database in which related information between bearing information and a remaining life of the bearing is accumulated, and based on the database and the bearing information received by the bearing information receiving unit, the remaining life of the bearing The bearing diagnosis system according to claim 6 , wherein:

Images